Currently, the CHT 4.x line supports running on Chrome 90+. This means that even devices running out-of-date versions of Chrome (or the Android System Webview) still reliably work with the CHT. (Note that as of today, the latest version of Chrome is 141.)
Unfortunately, the latest version of the Angular framework, which the CHT depends on, requires at least Chrome 107. To avoid being blocked from upgrading to the latest version of Angular (with new features and bug fixes), I am proposing that in the 5.0.0 major release we raise the minimum supported Chrome version for the CHT from 90 to 107. This means that the CHT web application would no longer be guaranteed to work on Chrome versions older than 107. The CHT app will warn users when logging in on an unsupported version of Chrome that the app may not function correctly.
To gauge the impact this may have on your users, you should check what version of Chrome/WebView is being used. The /api/v2/export/user-devices api endpoint provides this data in the browser.version property. However, the performance of this endpoint is poor on instances with a high number of users. @mrjones has developed a python script that can be used to help collect the relevant data. See the GitHub issue thread for more information.
Please check your instance and report back here if this change would impact your users! 
To be clear, it is recommend that users always be running the latest browser version and that their device be regularly updated as new versions of Chrome are released frequently. This is crucial because it provides users the most secure web browsing experience. The CHT guarantees backwards compatibility to older versions of Chrome because we recognize that in some circumstances and on some devices it is not feasible to keep the browser version continuously up to date. However, we recommend staying up to date whenever possible.